| rsc | b2ad2ef | 2005-01-04 22:30:59 +0000 | [diff] [blame] | 1 | #include <u.h> |
| 2 | #include <libc.h> |
| 3 | |
| 4 | int multi; |
| 5 | int nlines; |
| 6 | char *status = nil; |
| 7 | |
| 8 | int |
| 9 | line(int fd, char *file) |
| 10 | { |
| 11 | char c; |
| 12 | int m, n, nalloc; |
| 13 | char *buf; |
| 14 | |
| 15 | nalloc = 0; |
| 16 | buf = nil; |
| 17 | for(m=0; ; ){ |
| 18 | n = read(fd, &c, 1); |
| 19 | if(n < 0){ |
| 20 | fprint(2, "read: error reading %s: %r\n", file); |
| 21 | exits("read error"); |
| 22 | } |
| 23 | if(n == 0){ |
| 24 | if(m == 0) |
| 25 | status = "eof"; |
| 26 | break; |
| 27 | } |
| 28 | if(m == nalloc){ |
| 29 | nalloc += 1024; |
| 30 | buf = realloc(buf, nalloc); |
| 31 | if(buf == nil){ |
| 32 | fprint(2, "read: malloc error: %r\n"); |
| 33 | exits("malloc"); |
| 34 | } |
| 35 | } |
| 36 | buf[m++] = c; |
| 37 | if(c == '\n') |
| 38 | break; |
| 39 | } |
| 40 | if(m > 0) |
| 41 | write(1, buf, m); |
| 42 | free(buf); |
| 43 | return m; |
| 44 | } |
| 45 | |
| 46 | void |
| 47 | lines(int fd, char *file) |
| 48 | { |
| 49 | do{ |
| 50 | if(line(fd, file) == 0) |
| 51 | break; |
| 52 | }while(multi || --nlines>0); |
| 53 | } |
| 54 | |
| 55 | void |
| 56 | main(int argc, char *argv[]) |
| 57 | { |
| 58 | int i, fd; |
| 59 | char *s; |
| 60 | |
| 61 | ARGBEGIN{ |
| 62 | case 'm': |
| 63 | multi = 1; |
| 64 | break; |
| 65 | case 'n': |
| 66 | s = ARGF(); |
| 67 | if(s){ |
| 68 | nlines = atoi(s); |
| 69 | break; |
| 70 | } |
| 71 | /* fall through */ |
| 72 | default: |
| 73 | fprint(2, "usage: read [-m] [-n nlines] [files...]\n"); |
| 74 | exits("usage"); |
| 75 | }ARGEND |
| 76 | |
| 77 | if(argc == 0) |
| 78 | lines(0, "<stdin>"); |
| 79 | else |
| 80 | for(i=0; i<argc; i++){ |
| 81 | fd = open(argv[i], OREAD); |
| 82 | if(fd < 0){ |
| 83 | fprint(2, "read: can't open %s: %r\n", argv[i]); |
| 84 | exits("open"); |
| 85 | } |
| 86 | lines(fd, argv[i]); |
| 87 | close(fd); |
| 88 | } |
| 89 | |
| 90 | exits(status); |
| 91 | } |
